Remote Sensing of Upwelling in the Arabian Sea and Adjacent Near-Coastal Regions

Upwellingis a dominant mechanism in the Arabian Sea that occurs annually during southwest monsoonsummer season. This results in abundance of phytoplankton and zooplankton in the region and has profound influence on the coastal fisheries. During the southwest monsoon, an intense low-level wind jet blows diagonally across the Arabian Sea generating coastal upwellingalong the coasts of Somalia, Oman and the southeastern Arabian Sea. In this study, a synergy of different parameters like sea surface winds, chlorophyll (chl-a), sea surface temperature (SST) and sea level anomaly (SLA) retrieved from remote sensing were used to make a more detailed analysis on upwellingfeatures for the summer seasons of the years 1982–2015. From the analysis, it is observed that upwellingin the Arabian Sea is not homogeneous across the basin despite being driven by monsoonwinds. During the study period, Ekman transport, SLA and SST anomaly showed positive trend, whereas chlorophyll showed negative trend of varying strengths. Increased Ekman transporthas not generated increased productivity indicating the role of other governing mechanisms on the availability of nutrients in the region.